add zlib as host dep for compiled packages

Author: daler

bioconda_utils/bioconductor_skeleton.py

@@ -943,6 +943,11 @@ def sub_placeholders(x):
             additional_host_deps.append('libblas')
             additional_host_deps.append('liblapack')
 
+            # During the BioC 3.20 builds, which also corresponded to updates
+            # in pinnings, there were quite a few issues where zlib was
+            # missing.
+            additional_host_deps.append('zlib')
+
         additional_run_deps = []
         if self.is_data_package:
             additional_run_deps.append('curl')